Clutch assemblies are known to be integral parts of vehicle transmissions. Clutch housings and hubs define an annular wall circumscribing a housing axis. The annular wall defines a plurality of splines that extend from an open end to a floor of the housing, and are generally parallel to the axis. The splines engage clutch plates in a known manner to shift transmission gears in response to an accelerating or decelerating vehicle.
Presently, splines are formed in the annular wall of the housings by a series of die presses or in a progressive die. These dies are known to be exceedingly expensive, requiring a press having a high tonnage and associated transfer system for moving the pre-form to the sequentially arranged dies.
Additionally, soft or low strength sheet metal is required to allow the dies to form each of the splines. Still further, because the splines are formed in a die press, die relief is required of each spline to facilitate separating two halves of the die after formation. This requires each spline to have a trapezoidal configuration, where a work surface is substantially angled to the annular wall providing die relief. Due to the trapezoidal shape required of each spline for proper formation, a limited number of splines can be formed in the annular wall, reducing surface area of contact between the splines and the clutch plate.
Therefore, it would be desirable to provide a new form of spline to resolve the problems associated with the prior art spline configuration clutch housings and hubs.